The Medical Scientist Training Program (MSTP) is committed to training the next generation of scholars and leaders in the biomedical sciences by providing students with access to the very best resources of the University of Chicago. Chicago's distinctive interdisciplinary approach encourages students to explore their medical and research interests in the broadest possible terms in medicine, biology, the social sciences and the physical sciences. The University of Chicago was among the first schools to obtain federal funding in 1967 for a MSTP. Currently, we are in our 45th year of uninterrupted funding and have graduated 255 physician scientists. Our trainees have made many fundamental contributions to our understanding of biology and human disease resulting in numerous papers in Nature, Science, Cell, Immunity and the Proceedings of the National Academy of Sciences. Our graduates have gone on to lead important departments and academic units including the MSTPs at UCSF, Stanford, Harvard and Emory. Two of our trainees have been elected to the National Academy of Sciences. Currently 57 individuals, from all over the country, are enrolled in the program of which 37% are women and 7% are URMs. However, we have initiated several programs to enhance diversity and 3 of our 11 incoming students, or 27%, are URMs. In 2012, we had a large applicant pool of 438 students from which we successfully recruited students of outstanding academic promise. Therefore, we are requesting 35 NIH-supported trainee slots for years 39-43. This level of support, in conjunction with substantial and ongoing support from the University of Chicago Biological Sciences Division, will ensure that at least 10% of the total incoming Pritzker Medical School Class are trained as physician scientists. Relative to our institutional support, the requested NIH investment would be reasonable, constituting only 27% of our anticipated budget. Since the last funding submission in 2009, significant changes in the University of Chicago MSTP have been implemented. This proposal details how the MSTP administration has been completely overhauled to improve student recruitment, mentoring and student involvement in governance. As described, several new initiates have been undertaken to enhance the rigor and productivity of graduate training, fully integrate the graduate and medical school curriculums, lessen the time to degree and to enhance both the recruitment and retention of URMs. We also provide compelling and detailed evidence on the superb quality of our students and the outstanding research environment at The University of Chicago that is uniquely configured to support interdisciplinary programs such as the MSTP.